I've found an issue/problem with what I've written below, so for now, don't follow anything!
I'm trying to solve it and will post a proper solution soon.
I've discovered that "-1" tells the game to select "random civ", so "-1" won't work... and probably no number in the negative All the civs have an ID number. If you have 18 default civs, then the assigned number are from 0 to 17. If you have more default civs, then the same rule applies, which means that the lowest ID number is always "0", and goes to, say, 24, if you were to have 25-default civs etc.
I have found a way to assign your custom civ in the user config settings but in order to do that your custom civ needs an ID number, but assigning a custom civ an ID number no longer makes the civ a custom one and the game recognizes it as a default civ (but you can't play a default game using it, so don't bother; it only shows up in the civ-list). I thought that if I assigned my custom civ, say, ID number 98, then went into my config.ini and typed in "98", then it would always place that civ as the selected one, but it won't appear on the custom-civ list at all. So, my deduction is that ANY civ with an ID number means that it's a default civ, and any civ without a default ID number means that it will show up on the Mod-User-Game civ-list for selection. SO, any civ (custom or default) either has an ID number or doesn't, which the game recognizes as default-civs and custom-civs... no exceptions.
For now, everything I've typed below is worth the "toilet paper" it's written on. I'll fiddle around with this custom-civ matter when I have more time. I'll leave all the text there for now and consider deleting my post if no solution reveals itself.
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For information's sake --
I couldn't help but fiddle around with the .xml files, both the default Civ 5 .xml files and my custom civilization's .xml files... and I stumbled across a semi-solution.
Although I still can't insert my custom civ into the slot as the default-user-civ for starting any new game, I did find a sort-of-compromise...
my custom civ now appears at the very top of the list-of-all-the-civs (custom and default). *YAY*
In fact, it's fairly straight forward and simple for anyone to do, if they choose, so as long as you follow the steps.
(always backup your file and test to see if it works as you make any changes!).
My computer/Operating System is Windows7 and also has an XP-mode too.
Step 1 - Go to your custom civilization's folder found in the "Documents" folder -- My location happens to be --
C:\... ... \Documents\My Games\Sid Meier's Civilization 5\MODS\[your custom civ's folder name]\
-- for other Operating Systems the location will be slightly different, but still found under the "Documents" or My Documents" folder (which is the default location where all the custom stuff is kept)
So find your custom civ's folder, then open it to see the folders within your custom-civ folder.
Step 2 - Inside your custom-civ's folder you should find a folder named "XML", open it up.
Step 3 - Inside that "XML" folder you should see a folder named "Civilizations", open that up.
Step 4 - Inside the "Civilizations" folder you should see 2 files. These files are critical to your civilization working properly!
The file we want to make a small edit to is named "Civ_[name of your custom civ].xml"
And at this point, before you edit anything, I highly recommend making a backup copy of this file!
If you need to know how to copy the file -- Highlight it, right-click on that file you highlighted and select "copy" from the drop-down menu. Then left-click on the white portion of your screen inside the folder so that you "unhighlight" the folder. Right-click again and this time, from the drop-down menu choose "paste". It should make a duplicate copy of the file you just copied.
Step 5 - Open the ORIGINAL file, "Civ_[name of your custom civ].xml" (not the copy you just made). You may need to open it in notepad or some kind of text/writing application that allows you to edit the text inside the file.
Step 7 - the edit - At the top of this file you should see a bunch of text that looks similiar to what I've pasted below... except that the information on each line will be related to your custom civ (I'm using my civ info as an example).
Example: "<Type>CIVILIZATION_[your civ name]</Type>"
Step 7.5 - Adding a new line into your custom civ's information...
...so that the custom civ you like using the most will appear at the very top of the list (but not the default starting civ). You'll still have to click on it to select it, but at least it's not at the bottom of your list anymore. *smile*
So, immediately below in the bunch of data you see I've highlighted a line in RED. That line NEEDS to be added into your custom civ's file... AND you need to do it accurately with no mistakes, no spaces, and no extra character or numbers etc. Do it exactly as you see it below... the line is:
~ ~ ~ ~ ~ ~ ~
~ ~ ~ ~ ~ ~ ~
The number is a "minus 1" or "-1" in between the > <
The reason for this is because all of the default civilizations in the game have identification numbers assigned to them... from 0 --> to (at least) 18. The higher the number, the lower on your civ-list the civilization will be.
WARNING -- DO NOT EDIT THE DEFAULT-CIV ID NUMBERS, THIS WILL MESS UP YOUR GAME... LEAVE THEM ALONE.
So, by adding a line with a -1, that puts your custom civilization at the top of the list. Add that line in, SAVE the file, start up your civ 5 game and see if your custom civ is at the start of the list -- UNDER "MOD" GAME SETUP, not the default game setup.
Although I haven't tested my next theory out, I would think that if a person had 2 or 3 or more custom civs, you could essentially add the same line into each separate civ's file to have all your custom civs in-a-row at the top of the list -- but you would have to change the number that you've added so that each one is specifically different, for example...
~ Let's say you have 3 new custom civs... named A, B and C.
~ You want A at the top of the list, followed by B, then C.
~ To do this, the lowest-custom-civ-on-your-list gets the ID number "-1". The next civ closer to the top of the list gets the ID number "-2", and the top civ on your list gets ID number "-3".
Since I enjoy one particular custom civ in my game, I have the appropriate ID number assigned to it and it's at the top of my list of civs. The above method should work for placing multiple custom civs at the top of your list when you start a new mod-game, but please don't hold my feet to the fire. *giggling* It DOES work using only one custom civ, but for multiples, you'll have to be the Guinea Pig to test it out. As I say, always backup your files/work before edits--and always test the changes before comitting yourself.
It's taken a little while to type this stuff in here, but I figured since I found a semi-solution, why not post it and maybe it would help others . *smile*
I still haven't found a way to make my custom civ the default-choice in the user game setup (without actually having to click on it to select it). Nor, have I figured out if I can add a line(s) into my game's configuration-file so that my custom civ is always my default. For now, this is an ok compromise for me.
Enjoy your game!